A known conventional system disclosed, for instance, by Japanese Patent Laid-Open No. 2002-73153 diagnoses a vehicle condition within the vehicle and, if it is anticipated that a fault may occur, transmits relevant information to a servicing institution via a communication device. Before the vehicle becomes unable to run on a road, the conventional system makes it possible to avoid an inconvenience, which may arise out of a vehicle fault, by prompting an user to take emergency countermeasures or to bring the vehicle into a servicing institution.
However, the above conventional system finishes a vehicle fault diagnosis within a vehicle, and communicates with an external institution only when it transmits fault diagnosis results. As such being the case, the above conventional system needs to store the whole information necessary for fault diagnostic processing within the vehicle.
Further, if a fault occurs to affect the vehicle's run, the above conventional system supplies information to an external institution even if the severity of the fault is low. When the intended purpose is to prevent the vehicle from becoming disabled, the vehicle does not always have to transmit the information to an external if the severity of the fault is low and does not immediately disable the vehicle. In this respect, the above conventional system unnecessarily increases the load on a vehicle's information process.
The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a vehicle fault diagnostic system that is capable of taking early countermeasures against a vehicle fault and reduces information processing load on the vehicle by establishing communication between the vehicle and an external institution.
Japanese Patent Laid-Open No. 2002-202003 discloses a system that chronologically stores information regarding to learning values which are outside a specified range, evaluates the stored information, and notifies the user of a fault that is about to occur. The above document also discloses a technology for transmitting relevant data to a vehicle dealer to prompt for early response.
Further, Japanese Patent Laid-Open No. 2002-250248 discloses a system that exercises recovery control to inhibit the abnormality from spreading or expanding not only reports the abnormality when any abnormality is diagnosed.